Chair



3- w. A. SENGPIEL CHAIR Filed April 20. 1931 2 Sheets-Sheet l Patented May 16, 1933 UNITED STATES PATENT 1 OFFICE WILLIAM A. SENGI'IEL, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOB 1'0 THE m8 COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION 01' DELAWARE cnua Application filed April 80, 1931- Serial No. 581,280.

My invention relates to chairs of the type wherein the seat is pivotally mounted upon its su port and wherein also the back may be ad usted relatively to the seat. The chair 5 is of a type largely used by operators of typewriting machines and those of certain constructions are sometimes referred to as posture chairs because of the fact that the backs thereof automatically adjust themselves into position to support the back of a person sittm therein.

It is desira 1e that chairs of this kmdbe of a character such that they ma be adjusted to suit the form and buil of -the person usin the same and also of a character such t at the back will remain in contact with a person using theicha'ir and sitting on the samein the normal and usual The general object of the invention is to provide means of novel construction by which the pivotal movementv of the seat and back of the chair may be controlled. To best provide for the comfort of the 25 person using the chair italso is'an. object of the invention to provide achair having means of novel construction for causing the upper part of the back of the chair to move backward or forward in a certain desirable ratio to the corresgonding movements thereof at its lower en Without undertaking to point. out and explain at the present time the many and various objects of the invention, I shall pro- 3 ceed with a detailed descri tion thereof cen found to operate most satisfactorily and successfully in practice.

In the drawings:

Fi 1 is a view in central vertical s'ectiona elevation of ajchair embodying the invention;

Fig. 2 is a similar view showing the parts of the structure in different positions from those in which they are shown in Fig. 1;

Fig. 3 is a horizontal sectional view taken on the line 33 of Fig. 1; and

Fig. 4 is a view in elevation of a fragmentar portion of the structure showing more 0 early certain details thereof.

In the drawings I have shown at 1 the supporting pedestal of the chair of known construction which is adapted to receive and ad ustably support a spindle 2 which is provided at its. upper end with a head 3 comprising side portions 4' and a rear crosswise extending portion 5. An le irons 6 are secured on the outer sides 0 the u per' edge portions of the sides 4, the top orizontal flange of the said angle irons overlying the upper edges of the sides 4. The parts 2, 3 and 6 may be referred to as a whole as the chair iron. The an le irons or arms 6 aresecured to the sides 4I y rivets as indicated at 7. The front end portions of the angle irons constitute arms and are flared outwardl and laterally as shown at 10 in Fig. 3. e front ends of the angle irons terminate short distances inwardly of the front edge of the seat 11 of the chair and are connected to the said seat by means of a pivot rod 12 and ears'or lugs 13 which are securedv to the under sideof the seat 11 in adjoining relation to the front ed terminate in adjoining relation to the rear edges of the sides 4 and substantial distances in front of the rear edge of the seat. The seat is provided upon its under side near its rear edge with downwardly extending lugs or projections 15 which at their lower ends are pivotally connected by a pivot rod 16 with the rear ends of a link 17 comprising side members 18 which are connected to gether by means of crosswise extending parallel bars 20 which are spaced from each other as shown. These bars are located short distances from the rear ends of the sides 18. The front ends of the sides are pivotally connected by means of a pivot rod 21 to the sides 4 of the chair iron. The

' said rod also extends through the vertical sides of the angle irons 6. It may be noted that the pivot rod 21 extends in parallel relation to the pivot rods 12 and -16 and that it is located somewhat nearer to the pivot rod 16 than it is to the pivot rod 12. However, it will be understood that the position of the pivot rod 21 may be. changed somewhat, if desired, without departing from the invention and without changing in any substantial manner the principle of operation.

For the purpose of holding the chair in its normal position which is that shown in Fig. 1 of the drawings, I have provided a tension bolt 25 which extends through a squared or other polygonal-shaped opening 26 in the portion 5 of the chair iron previously referred to. The head upon the rear end of the bolt 25 is seated against the rear side of the part 5 and thus limits the movechair.

ment of the bolt toward the front of the The bolt is provided with a couple of bearing members 27 and 28 which are slidable thereon. The rear bearing member 27 is provided upon its rear side with a wide V-shaped groove 29 with which engages the wedge-shaped edges 30 provided upon the front side of the projection 31'w-hich cxtends downwardly from a cross bar '32 which is connected at'its opposite ends to and supported by the sides 18 of the link 17. The said bar 32is located near the front ends of the sides 18. The wedge-shaped projections 30 are located onthe opposite sides of an elongated opening 34 provided in the said projection 31. The bearing member 28 is retained upon the'tension bolt 25 by means of a tubular nut .35 which has screw-threaded connection with the front end of the said bolt. The rearend 0f the tubular nut 35 bears against the outer side of the member 28. A spring 37 is coiled about the bolt 25. The rear end of the spring 37 is seated against the front side 'of the member 27,- while the front end there- 'of is seated against the rear side of the member 28. By adjusting the tubular nut 35 upon the outer end of the bolt 25 adjustment of the bearing member 28 may be effected either toward the rear or toward the front of the chair structure. The adjustment of the said member 28 varies the tension of the spring 37. Said spring normally is under compression and its tendency to expand tends to cause pivotal movement of the chair seat .upwardly and of the back 40 thereof toward the front. If the tubular nut 35 is screwed inwardly, the tension of the spring 37v is increased so that greater force is exerted tending to cause pivotal movement of the seat 11 and back 40 toward the front. When the tension of the spring 37 is increased by the rearward adjustment of the member 28, the force necessary to cause a backward tilting movement of the seat 11 and back 40 is increased.

The back 40 comprises a backrest 41 which is supported at the upper ends of the sides 4-2, the said backrest 41 constituting a connection between the upper ends of the opposite sides. The lower ends of the sides 42 are connected together by an outwardly curved cross bar 43 and also by a metal bar 44 which is also curved outwardly and is located inwardly of and in approximately concentric relation to the outer bar 43. The opposite ends of the bar 44 are connected to the lower ends of the sides 42 of. the chair back by means of screws 45.

For connecting the chair back 40 to the chair seat 11 I have provided a. coupling member of shallow box shape the rear or bottom of which is curved and is concentric with the central portion of the cross bar 44. The front side of the central portion of the'cross bar 44 is seated against the rear side of the coupling member 50. The length of the member 50 vertically-is substantially greater than the width of the bar 44. The rear closed or bottom end of the member 50 is provided with spaced vertical parallel slots 51 into and through which projections or lugs 52 project from the front side of the bar 44, the said lugs being integral with or otherwise connected with the said bar 44. The front end portions of the projections or lugs 52 are provided with holes 53 therethrough through which extend vertical supporting rods 54 the upper and lower ends of whichare secured or fastened to the top and bottom portions of' the coupling 50. The opposite sides of the coupling 50 are provided with projections or ears 56 which are located in approximately the same horizontal plane, the outer ends of which are provided with openings with which the outer ends of the pivot rod 16 are in engagement. It will be recalled that the outer end portions of said rod are also in pivotal engagement with the rear ends of the sides 18 of the link 17.

and with the lower ends of the downwardly extending projections or cars 15, the latter I being connected, at their upper ends to the. bottom of the seat 11'. the vertical adjustment of the back of the'chair, the lugs orcars 52 slide upon the uprightbars 54 The front side of the cross bar 44 is provided with beads orelongated projections 57 the inner sides of which constitute shoulders which engage the rear edge portions of the outer vertical sides of the coup-ling 50.

' These (shoulders constitute guides which supplement the guide rods 54 for directing and any position to which it may be adjusted vertically and "for releasing the same to permit adjustment thereof, I have provided a catch in the form of a pin 58 which is slidably mounted in a bushing 59 provided in an opening through "the bar '44. The said pin is adapted to" engage any one of a series of openings 60 arranged in vertical align- .ment in the rear side of the coupling 50;

The inner end of a lever 61 engages an opening which extends transversely of the pin 58. The said lever 61 is pivoted intermediate its ends upon a pivot 62 supported upon a post or projection 63 which projects rearwardly from the cross bar 44'. The lever 61 is located between the bars 43 and 44 and extends lengthwise thereof or horizontally. Its outer end is connected to the rear end of a link 64 which extends through an openin 65 provided in the cross bar 44. The fron end of the link 64 is connected to the inner end-of a manually operable lever 66 pivoted intermediate its ends upon a post or projection 67 which is mounted upon the bar 44 and extends toward the front. The outer end of the lever 66 is positioned so that it is readily accessible to a person, whether or not such person be sitting in the chair, for the purpose of moving, the same about its pivot. Such movement causes front or rear movement, as the case may be, of the inner end of the lever 66 to, cause lengthwise movement of the link 64 in one direction or theother.

Such lengthwise movement ofthe link 64 causes pivotal movement of the lever 61 so as to cause front or rear movement of the pin 58, depending upon whether or not it is desired to engage the said pin with or remove it from one of the openings 60 of the series ofopenings provided in the coupling 50. For the purpose of holding the outer end of the lever outwardly against the front side of the bar v43 to cause the inner end thereof to press the pin 58 inwardly, I

have provided a coiled spring 68 which is under tension so that its tendency to expand normally holds the inner endof the lever 61 in position to hold the pin 58 in engagement with one of the holes oro enings .60, "If the outer end of the lever 66 the outer end of the lever-61 h p ess d rearwardl cause to move toward the front .to cause rearward movement of the inner end thereof to remove the pin 58 from one of the holes or openings 60. When this has been accomplished the chairback may be adjusted 'vertically either downwardly or upwardly so as to position the back-rest portion 41 there'- of at an height which may be desired. This heig t will depend upon the length and conformation of the back of the person who may be using the chair.

For the purpose of causing ivotal move- 'ment of the chair back 40-w1th respect to the seat, I have provided a worm gear 70 which is located between the parallel spaced bars 20, previously referred to, and is mount- "ed upon and supported by the screwthreaded portion of a link 71 the rear end :of which is pivotally connected with ears 72 which project forwardly from about the middle or central portion of the coupling 50. The connection of the link 71 to the ears 72 is effected by means of a pivot 73. The worm gear 70 may rotate but being located between the bars 20 bodily movement thereof in the direction of its axis is prevented. Upon rotation of the said worm gear, axial or lengthwise movement of the link 71 is caused either toward the rear or toward the front of the chair, depending upon the direction of rotation of the Worm gear 70. For the purpose of rotating the worm gear I-have provided a worm 75 which is mounted upon a shaft 76 which is journaled in openings 77 provided in enlarged portions 78 of the sides 18 of the link 17. The shaft 76 extends transversely of the chair and is located in an approximately horizontal plane. The worm 75, in the con struction as illustrated, .is formed upon a sleeve or tubular portion-79 which is rigidl connected in any desiredinanner to the sha t 76. The opposite ends of the portion 79 are seated against the innersides of the enlarged portions 78 to thereby prevent axial movement thereof and of the shaft 76. Upon rotation of the shaft 7 6 and the worm gear thereon rotation of the worm gear 70 in one direction or the other'is caused and such rotation, as previously stated, causes lengthwise movement of the link 71 in one direction or the other. Such movement thereof causes pivotal movement of the back 40 about the pivot rod 16 to vary the tilt of the chair with respect to the seat 11.

' -If the seat 11 is caused to move down- .wa'rdly about the pivot rod 12 as when a person is sitting thereon, and -particularly if such person should lean back in the chair,

theapivot rod 16 and the rear end of the link .17 pivptally connected therewith are also depressed. The link 17 at such time pivots about the pivot rodf21. During such downjvard movementthe pivot rod 21 also moves a short distance toward the front of the chair therebyfcausing a corresponding movement of the link 17 To permit such move-- through the front end thereof and simultaneously the front end of the link moves slightly forwardly and upwardly, such latter movement being permitted by the oblong shape of the openings in which the opposite ends of the pivot 21 are journaled. As

the rear end of the link 17 moves down-, wardly upon the depression of the rear portion of the seat 11, the parallel spaced bars 20 together with the worm gear 7 0 not only move downwardly but pivot around rod 16 and move slightly forwardly with respect to a vertical line through the rod 16. Such movement causes corresponding pull on and forward movement of the adjusting link 71 to thereby cause pivotal movement of the coupling 50 and the back 40, mounted on the latter, about the rod 16. The pivot 73 is located a distance below and slightly in rear of the pivot rod 16. The distance between the said pivot and pivot rod is very small as compared with the length or height of the back 40. As a result the movement of the upper portion of the latter is accelerated and is quite great as compared with the .small inward movement toward the front of the pivot 73. The amount or extent of the pivotal movement of the link 17 with respect to the pivot rod 16 upon downward movement of the rear portion of the seat 11 is slightly increased by the provision of the extension of the openings in which the pivot rod 21 is supported upwardly as Well as forwardly. Upward movement obviously would increase the extent of pivotal movement of the link 17 about the pivot rod 16.

Upon depression of the rear portion of the seat 11 about its pivot 12, it will be apparent that even though the back 40were not pivotally mounted in the manner as shown but were rigidly connected with the seat it would move backwardly, the amount of such movement depending upon the extent of depression of'the rear portion of the seat, but such backward movement is greatly increased by connecting the back through the pivots 16 and 73 to the chair seat in the manner as shown and as above described. The movement of the pivot 73 toward the front relatively to the pivot 16 causes a supplemental or additional backward movement of the chair back upon depression of the seat which is relatively great as compared with the extent of the inward movement or movement toward the front of the piVOt 73.

It will be seen that by my invention I have provided a chair structure having means whereby automatic back and forth pivotal movements of the back are effected upon downward and upward movements of the rear portion of the seat thereof about the pivot which supports the front end of the chair seat.

However, while the invention has been described from the standpoint of the movement of the scat automatically varying the angular position of the back with respect thereto, it will be understood that the reverse is also true, and that the movement of the back will automatically vary the angular position of the seat relatively to it. In other words, the seat and back are so related that movement of one through a given angle automatically varies the position of the other.

Having thus described my invention what I claim and desire to secure by Letters Patent is:

1. In a chair, the combination of a seat, a support therefor, means pivotally connecting said seat to said support, spring means tending to oppose tilting movement of said seat in one direction, a back, means pivotally connecting the said back at its lower end to the rear end portion of said seat, and means for causing back and forth tilting movements of the said back relatively to the said seat upon the pivotal movements of the seat on the support under the influence of said spring means.

2. In a chair, the combination of a seat, a support therefor, means pivotally connecting the front portion of said seat to the said support, resilient means tending to cause upward movement of the rear portion of the said seat, a back, means pivotally connecting the said back to the rear portion of said seat; and means for causing backward and forward tilting movements of the said back relatively to the said seat upon the downward and upward movements of the latter about its pivot at the front thereof under the influence of said resilient means.

In a chair, the combination of a seat, a

support therefor, means pivotally connect ing the front portion of said seat to the said support, a back, a coupling to which the lower end of said back is secured, a pivotal connection between the said coupling and the rear portion of the said seat, and means for causing backward and forward tilting movements of the said coupling and back relatively to the said seat upon the downward and upward movements of the said seat.

4. In a chair, the combination of a seat, a support therefor, a pivotal connection between the said seat and the said support, a back, a link, pivot means connecting the lower end portion of said back and the rear end portion of said link to the rear portion I ward the front upon a downward movement openings provided in the said support and of' said seat, a pivotal connection between the front end of said link and the said support, and a second pivotal connection between said linkand the said back, the last named connection being located on oneside of a line connecting said pivot means and the pivotal connection between the front end of said link and the said support.

In a chair, the combination of a seat, a support therefor, a pivotal connection between the. front portion of said seat and the saidsupport, a back, a coupling interposed between the lower portion of said back and the rear portion of said seat, a link, means for pivotally connecting the front end of 8. In a chair, the combination of a seat,a support therefor, a pivot connecting the front portion of said seat to the front of said supportya back, a link, a pivot connecting the lower portion of said back and therear end of said link'to the rear portion of said seat, a pivot extending through the front end of said link and an elongated openin in the said support whereby the front en of said link is movable "both toward the front and upwardly toward-the said seat, a projection extending downwardly from the front end portion of the said link, yielding means in engagement with the said projection, which means operate through the said said link to the said support at a 'point in projection and the said link to cause or tend rear of the connection between the front portion of said seat and the said support, means pivotally connecting the said coupling and the rear end of said link to the rear portion of said seat, and a second pivotal connection between the said cou ling and the rear end portion of said link, t c said second pivotal connection between 'the said coupling, the said link and the said seat.

6; In a chair, the combination of a seat, a support therefor, a pivot connecting the front portion of said seat tothe said support, a back, ii link, a pivot connecting the rear end of said link and the lower portion of said back to the rear portionof said seat, a pivot extending through the front end of said link and an elongated opening in the said support at a point in rear of the pivot connecting the front portion of said seat to said support, means acting through the said link and tending .to cause upward movement of the rearportion of the said seat, the front end of said link being moveable toof the rear portion of said seat, and a second pivotal connection between the ,said back and the said link, the said'pivotal connection being located below the pivotal connection between the rear end of said link, the back and therearportion of said seat.

7.- In a chair, the combination of a seat, a support therefor, a pivot connecting the front portion of said seat to the said support, a back, a coupling interposed between the lower portion;- of said back and the rear portion of said seat, a link,-a pivot connecting the said coupling and the rear end of said link to the said seat, a pivot mounted in connecting the front end of said link to the said support, the openings being oblong and extending 1n an .gupwardly inclined direc- 9" tion from-the rear toward the front, and a pivotal connection between the rear end portion of said link and the said coupling, the

pivotal connection being located below the to cause upward movement of the rear portion of the said seat, and a pivotal connection between the rear portion of said link and the said back, the said last named connection being located below the pivotal connection between the rear end of said link, the said back and the said seat. I

9. In a chair, the combination of a seat, a support therefor, a pivot connecting the front portion of said seat to-the front r-- tion of the said support, a back, a lin a pivot connecting'the rear end of said link to the said back and to the rear end portion of the said seat, a pivot connecting the front end of said link to the said support at a point approximately midway between the,

the rear portion of saidseat, a second con- Q nection between the rear portion of said link ,and the said back, and means for effecting adjustment of said connection to cause pivotal movement of said back about the pivot of 'said seat.

a support therefor, a pivotal connection between the front portion of the seat and said support, a back, a link, pivot means connecting the rear end of the link and the lower portion of said backito the rear portion of said seat, a ivotal and slidable connection between the out end of said link and said support and a second pivotal connection be tween die said link and the said back, 10- cated on one side of a line'eonnecting said pivot means and the connection between the front end of said link and said sup rt.

In testimony that I claim the oregoing as my invention, I have hereunto'signed my name this 17th da of April, A. D., 1931.

. I'M A. SENGPIEL.

wlatter connection beinglocated below the pivot between the rear end of said link, the 5 coupling and the rear portion of said seat.

105 between the latter and the rear end portion Y 

